T-test assess whether the means of two groups are statistically different from each other.
1. Click Analyze, then click Compare Means. For this demonstration, we will perform a independent samples t-test, therefore click on Independent-Samples T Test.
2. The Independent-Samples T Test dialogue box will appear.
3. For this demonstration, we want to test if the mean age between those who are married and those who are not are statistically different.
3.1. Select Age on the left column and click the forward arrow to move it to the Test Variable column.
3.2. Age is selected as the Test Variable.
3.3. Select Marital status on the left column and click the forward arrow to move it to the Group Variable column.
3.4. Marital status is selected as the Grouping Variable.
4. SPSS does not know automatically what two groups you want to compare means. To tell SPSS which groups we want, click Define Groups.
5. Enter 0 for Group 1 and 1 for Group 2.
For this dataset, 0 indicated that a participant was unmarried and 1 indicated that they were married.
6. Click Continue.
6.1. Optional: You can select additional options or bootstrap.
7. Click OK.
8. The results will appear in the Output window.
